BETA(3)-ADRENERGIC-RECEPTOR ALLELE DISTRIBUTIONS IN CHILDREN, ADOLESCENTS AND YOUNG-ADULTS WITH OBESITY, UNDERWEIGHT OR ANOREXIA NERVOSA

OBJECTIVE: The missense mutation (64Trp to 64Arg) in the beta(3)-adren ergic-receptor has previously been described to confer a genetic predi sposition to the development of obesity. DESIGN: To test the hypothesi s we evaluated allele frequencies in children, adolescents and young a dults who belonged to different weight groups that were delineated wit h percentiles for the body mass index (BMI; kg/m(2)). SUBJECTS: 99 und erweight probands (BMI less than or equal to 15th percentile). 80 norm al weight probands (BMI: 5th-85th percentile). 238 obese children and adolescents (BMI greater than or equal to 97th percentile). 84 patient s with anorexia nervosa (AN). MEASUREMENTS: The cohorts were screened by polymerase chain reaction with subsequent restriction fragment leng th polymorphism (PCR-RFLP) analysis. Data were statistically analysed for association. In addition to these case control studies, the transm ission disequilibrium test (TDT) was applied to 80 families of obese p robands and to 52 families of patients with AN. RESULTS: Both the test s far association and linkage were negative. The Trp64Arg allele frequ encies in the three weight groups (obesity: 0.071; normal weight: 0.08 1; underweight: 0.056) and the AN patients (0.054) were similar. Extre mely obese individuals showed no excess of the Trp64Arg allele. No hom ozygotes for the Trp64Arg allele were detected. CONCLUSION: Heterozygo sity for the Trp64Arg allele is not of major importance in regulation of body weight in individuals younger than 35 y. Additionally, the ext reme obese subgroup is not enriched for the polymorphism.